The first recommendation I have is to make sure that with your TRX or bodyweight workouts, that you put together some sort of plan for how you are going to progress. Adding more repetitions only counts as progression for a while, then you have to add more difficulty. Weight lifting plans all include adding a certain amount of weight over time; bodyweight workouts should increase difficulty over time, in a structured way.
Second, sprints only need 50-100 yards. If you have a large lot, you might be able to do them in your yard, but you should be able to do them back and forth on your street. It's not as much fun as trail running, but still effective.